The objectives of this proposal are: 1. To continue the Epi-Stat program for the development of a statistical base of information (tumor registry) on patients diagnosed and/or treated at the Yale Comprehensive Cancer Center which is compatible with the Centralized Cancer Patient Data System and which is a resource for clinical and epidemiological investigations in cancer. 2. To improve the quality control of data entered in this system. 3. To investigate areas where the data base may be expanded in order to increase the research potential of the tumor registry. 4. To develop and carry out through the Centralized Patient Data System, protocols for collaborative studies of cancer patient characteristics, and natural history, treatment and etiology of cancer.